Field of the Invention
The invention relates to a power diode including a semiconductor body having an inner zone of a first conduction type, a cathode zone of the first conduction type adjoining the inner zone and having a higher doping concentration than the inner zone, at least one first coupling zone of the first conduction type adjoining the inner zone and having a doping concentration higher than that of the inner zone and lower than that of the cathode zone, and an anode zone of the second conduction type adjoining the first coupling zone and having a higher doping concentration than in the first coupling zone.
An FCI (Field-Controlled-Injection) diode of the type mentioned in the introduction is known, for example, as a Read diode and is described by K. T. Kaschani and R. Sittig in a paper entitled "How to avoid TRAPATT-Oscillations at the Reverse Recovery of Power Diodes", in CAS '95, pp. 571-574, Sinaia, 1995. The subject matter of that document is hereby expressly incorporated by reference in the present application.
The Read diode was originally developed as a high-frequency component for generating IMPATT oscillations. The FCI concept is explained below in conjunction with FIG. 1 with reference to the known Read diode in a specific construction as a pin power diode. In such a pin power diode, the electric fields of a high-field zone and a low-field zone are through a space charge of a coupling zone. However, space charge coupling has proved to be difficult to manipulate for the commutation of power diodes, since the space charge coupling is extremely temperature-dependent. Accordingly, it is difficult to use such pin power diodes in practice.